Acceleration-actuated striking mechanism

ABSTRACT

A high force striking mechanism actuated in response to application of axial acceleration forces acting thereon. The mechanism includes a spring-biased cam disposed for rotation upon release thereof from a first restrained position. The cam is held in the restrained position by a weighted member having a spring secured thereto and extending therefrom in interfering engagement with the cam. Acceleration forces acting on the weighted member causes displacement thereof for release of the spring-biased cam from its restrained position for rotation of the cam. A first spring-biased arm supports a spring-biased striker arm in cocked position against a cam surface provided on the first arm. A cam follower carried on the first arm is disposed for movement along the periphery of the cam until it falls into a cam slot thereon to cause displacement of the first arm. The spring-biased striker arm is released as a result of the displacement of the first arm to cause the striker to impact on a percussion squib or other mechanisms with high force.

United States Patent [72] Inventors Bernie J. Cobb;

Frank R. Skinner, Huntsville, Ala. [21] Appl. No. 731,518 [22] Filed May 23, 1968 [45] Patented Mar. 2, 1971 73] Assignee the United States of America as represented by the Secretary of the ARMY [54] ACCELERATION-ACTUATED STRIKING MECHANISM 5 Claims, 5 Drawing Figs. [5 2] U.S. Cl [51] Int. Cl

F42c 9/04 [50] Field ofSearch 102/82, 83, 84

[56] References Cited UNITED STATES PATENTS 1,309,333 7/1919 Ohlson 102/83 1,319,304 10/1919 Ohlson 102/84 2,514,499 711950 Kharasch et a1. 102/84 Primary Examiner-Samuel F einberg Assistant Examiner-Jerald .l. Devitt Attorneys-l-larry M. Saragovitz, Edward J. Kelly, Herbert Her] and Harold W. Hilton ABSTRACT: A high force striking mechanism actuated in response to application of axial acceleration forces acting thereon. The mechanism includes a spring-biased cam disposed for rotation upon release thereof from a first restrained position. The cam is held in the restrained position by a weighted member having a spring secured thereto and extending therefrom in interfering engagement with the cam. Acceleration forces acting on the weighted member causes displacement thereof for release of the springbiased cam from its restrained position for rotation of the cam. A first spring-biased arm supports a spring-biased striker arm in cocked position against a cam surface provided on the first arm. A cam follower carried on the first arm is disposed for movement along the periphery of the cam until it falls into a cam slot thereon to cause displacement of the first arm. The spring-biased striker arm is released as a result of the displacement of the first arm to cause the striker to impact on a percussion squib or other mechanisms with high force.

Patented March 2, 1971 FIG. 4

Bernie J. Cobb Frank R. Skiinner,

yv NTORS.-

ACCELERATION-ACTUATED STRIKING MECHANISM DEDICATORY CLAUSE The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

BACKGROUND OF THE INVENTION The device of the present invention is a mechanism for providing a timing and actuating function in rockets. In meteorological rockets, for example, a separation function is required to deploy the instrument package for sensing the atmospheric conditions. Such separation function is achieved at a desired time after the rocket has experienced a predetermined value of acceleration (launch acceleration). The device of the present invention, when utilized in such meteorological rockets, acts in response to accelerations to move a striker arm, a predetermined time after the accelerations, for impact with a percussion squib for initiating such separation function. If desired, the detonator may be replaced by a sharp point to break a frangible valve or the like.

A conventional spring-driven timing mechanism is marketed by M.I-I. Rhodes, Inc., Hartford, Connecticut, and includes a trip lever which moves across an arc at the end of a predetermined time interval. The Mark-Time 1,900 Series spring driven mechanism is typical of such a device and is disclosed in the M. H. Rhodes catalogue, Timers and Time Switches for Appliances and Industry.

The present invention provides improvements to such conventional mechanisms, including means for actuating the timer in response to axial accelerations acting thereon; and, a double cam action which provides for increased striking force in the striking mechanism.

SUMMARY OF THE INVENTION A device for initiating movement of a high force striker arm from a first cocked position to a second position of impact, at a controlled time interval after the device has been subjected to acceleration forces. The device is actuated by the acceleration forces to initiate actuation of a timer, which controls rotation of a cam for a predetermined time interval, for displacement of a striker arm responsive to the cam rotation.

It is an object of the present invention, therefore, to provide an acceleration-actuated striker mechanism disposed for actuation at a present time interval responsive to the accelerations.

It is another object of the present invention to provide such a mechanism for providing a timing and actuating function in missiles.

Still another object of the present invention is to provide such a mechanism which will have sufficient mechanical advantages to allow high forces in the striker without overloading the timer by friction on the cam.

The above objects and attendant advantages will become more readily apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view illustrating the striker arm in cocked position prior to actuation of the device.

FIG. 2 is a view similar to FIG. 1 showing the striker arm displaced.

FIG. 3 is a sectional view along line 3-3 of FIG. 2 with the acceleration member in position prior to accelerations acting thereon.

FIG. 4 is a view similar to FIG. 3 with the acceleration member displaced.

FIG. 5 is a sectional view along line 5-5 of FIG. 2.

As shown in FIG. I, the acceleration actuated timer-striker typically includes a frame 12 for support of a cam 14 having a cam slot 15 therein. As more clearly shown in FIGS. 3

and 5, frame 12 includes a pair of plates 16 and 18 spaced in substantially parallel relationship. A central shaft 20 extends through bottom plate 18 upwardly through upper plate 16 for rotational support of cam 14. A plurality of stanchions 22 (FIG. 5) is secured between the plates for assembly thereof.

As seen in FIG. I, a tripping arm 24 is pivotally secured to plate 16 by a pivot pin 26 at one end 28 thereof. Arm 24 extends across plate 16 and is spring biased at the other end 30 to plate 16 by a spring 32. Tripping arm 24 is provided with a cam follower or bearing 34 and a second cam surface 36 for reasons described hereinbelow.

A striker arm 38 is pivotally secured to plate 16 at one end 40 thereof by a pivot pin 42 and extends across the plate, in a direction substantially transverse to tripping arm 24. Striker arm 38 is provided at its other end 44 with a striking device 46. A pair of springs 47 and 49 (FIG. 5) is secured to a stub shaft 48 secured to and extending through striker arm 38 and passing through a slot 50 in plate 16. Springs 47 and 49 extend from the stub shaft 48 for attachment to one of the stanchions 22 and a stanchion 23 carried on plate 16, for spring loading of the arm.

At the end 40 of striker arm 38, a latch arm 52 is disposed in pivotal relation by pivot pin 42. Latch arm 52 is provided with a weighted member 54 at the other end 56 thereof.

A torsion spring 58 is secured to weighted member 54 and is provided with a leg (FIG. 3) which extends through an opening 60 in plate 16 for engagement with a gear 62 carried between plates 16 and 18 on shaft 20'. Also carried on shaft 20, intermediate the gear 62 and plate 16 is a flat coil spring 64 which permits the cam 14 to be wound up to provide the rotation thereof. Spring 64 has oneof its ends secured to shaft 20 and its other end secured to the plate 16 for spring loading of cam 14.

In operation, striker arm 38 is moved to a cocked position as shown in FIG. I and cam 14 is wound on shaft 20 by inserting a winding key in a pair of openings 66 provided in the cam. Leg 55 of spring 58 is then placed in a position of engagement with gear 62 by inserting leg 57 of spring 58 in hole 60 to prevent rotation thereof. In this position, the cam follower 34 is in engagement with the periphery of cam 14 and tripping arm 24 is biased away from the cam shaft 20. Furthermore, striking arm 38 is in a position wherein stub shaft 48 is in engagement with cam surface 36 of tripping arm 24 and springs 47 and 49 are in tension.

Responsive to an axial force (acceleration) acting on the device, weighted member 54 is displaced from plate 16, as shown in FIG. 4, for release of leg 55 of spring 58 from gear 62 to activate the timer. Weighted member 54 is held clear of plate 16 by a second leg 57 of spring 58 engaging plate 16. The present time cycle begins, and as the timer spring unwinds, the cam on the face of the timer rotates. When slot 15 in cam 14 aligns with cam follower 34 on tripping arm 24, the tripping arm is forced down by spring 32. With the tripping arm in the new position the striker arm is free to move forward, releasing the energy in springs 47 and 49 for rapid displacement of the striker mechanism 46 in an arcuate path about pivot pin 42.

It is obvious from the foregoing that the present invention includes a low cost, acceleration actuated timer-striker mechanism having a double cam action to provide for a high striking force of the striking device. While the present application discloses the striker device being utilized as a detonator for firing a percussion squib, other variations may be resorted to, for example, the striker may be provided with a sharp point in place of the detonator to break a frangible valve; however, such modifications are within the spirit and scope of the appended claims.

We claim:

1. An acceleration-actuated, time-delayed, detonating mechanism comprising:

a. a frame having a cam rotatably secured thereon, said cam having a peripheral surface and a slot disposed thereon;

b. biasing means secured between said cam and said frame for biasing said cam for rotation thereof;

c. a first spring-biased arm pivotally secured to said frame and extending in a first direction thereacross, said first spring-biased arm having a first cam follower secured thereon for engagement with the peripheral surface of said cam, said first'spring biased arm also having a cam surface carried thereon between said first cam follower and the distal end of said first arm;

d. a spring-biased striker arm having a first end thereof pivotally secured to said frame said striker arm extending in a direction substantially transverse to said first direction, and having a second cam follower thereon for engaged relation with said cam surface of said first arm when said first cam follower is in the engaged relation said peripheral surface of said cam whereby said striker arm is retained in a first cocked position;

a third arm disposed in pivotal relation with the first end of said striker arm;

f. acceleration-actuated means carried on the distal end of said third arm, said acceleration-actuated means having locking means secured thereto and in engaged relation with said biasing means for preventing rotation of said cam, said acceleration-actuated actuated means disposed for displacement responsive to acceleration forces of a predetermined magnitude acting thereon for release of said locking means from said cam, whereby said cam is rotated by said biasing means for a predetermined time interval, to a position where said first cam follower falls in said slot on said cam to displace said first arm for disengagement of said second cam follower from said cam surface thereon, whereby said striker arm is released from said first cocked position to travel in an arcu'ate path to a second position of impact.

2. A mechanism as in claim 1 wherein said striker arm is provided with a detonator pin carried adjacent the distal end thereof.

3. A mechanism as in claim 2 wherein said acceleration actuated member is a weighted arm disposed in pivotal relation with one end of said striker arm.

4. A mechanism as in claim 3 including a shaft carried on said frame for rotatably supporting said cam thereon and a said biasing means is spring secured to said shaft and said frame to permit biasing of said cam for rotation thereof.

5. A mechanism as in claim 4 wherein said locking means includes a gear member secured to said shaft, a torsion spring secured to said weighted member, said torsion spring having first and second legs, said first leg being in engagement with said gear member for preventing said earn from rotating, said second leg disposed for engagement with said frame responsive to release of said first leg from said gear whereby said weight member is held in the displaced position responsive to displacement thereof. 

1. An acceleration-actuated, time-delayed, detonating mechanism comprising: a. a frame having a cam rotatably secured thereon, said cam having a peripheral surface and a slot disposed thereon; b. biasing means secured between said cam and said frame for biasing said cam for rotation thereof; c. a first spring-biased arm pivotally secured to said frame and extending in a first direction thereacross, said first springbiased arm having a first cam follower secured thereon for engagement with the peripheral surface of said cam, said first spring biased arm also having a cam surface carried thereon between said first cam follower and the distal end of said first arm; d. a spring-biased striker arm having a first end thereof pivotally secured to said frame said striker arm extending in a direction substantially transverse to said first direction, and having a second cam follower thereon for engaged relation with said cam surface of said first arm when said first cam follower is in the engaged relation said peripheral surface of said cam whereby said striker arm is retained in a first cocked position; e. a third arm disposed in pivotal relation with the first end of said striker arm; f. acceleration-actuated means carried on the distal end of said third arm, said acceleration-actuated means having locking means secured thereto and in engaged relation with said biasing means for preventing rotation of said cam, said accelerationactuated actuated means disposed for displacement responsive to acceleration forces of a predetermined magnitude acting thereon for release of said locking means from said cam, whereby said cam is rotated by said biasing means for a predetermined time interval, to a position where said first cam follower falls in said slot on said cam to displace said first arm for disengagement of said second cam follower from said cam surface thereon, whereby said striker arm is released from said first cocked position to travel in an arcuate path to a second position of impact.
 2. A mechanism as in claim 1 wherein said striker arm is provided with a detonator pin carried adjacent the distal end thereof.
 3. A mechanism as in claim 2 wherein said acceleration actuated member is a weighted arm disposed in pivotal relation with one end of said striker arm.
 4. A mechanism as in claim 3 including a shaft carried on said frame for rotatably supporting said cam thereon and a said biasing means is spring secured to said shaft and said frame to permit biasing of said cam for rotation thereof.
 5. A mechanism as in claim 4 wherein said locking means includes a gear member secured to said shaft, a torsion spring secured to said weighted member, said torsion spring having first and second legs, said first leg being in engagement with said gear member for preventing said cam from rotating, said second leg disposed for engagement with said frame Responsive to release of said first leg from said gear whereby said weight member is held in the displaced position responsive to displacement thereof. 